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arXiv quant-ph/9512011quant-phhep-thmath.QAq-alg
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量子物理中的混沌守恒问题

On the Problem of Chaos Conservation in Quantum Physics

V. P. Maslov, O. Yu. Shvedov

摘要:

本文给出了一种新的构造N元函数的N次$N^{-1/2}$幂渐近级数的方法,它是一类特殊类型方程柯西问题的解.当外部势为O(1)阶,粒子相互作用势的系数为1/N时,多粒子系统的多粒子Wigner、Schrödinger和Liouville方程都属于这种类型;这些势可以是任意光滑的有界函数。我们应用这种方法的N粒子状态方程对应的N次张量功率的抽象哈密顿代数的观测量。特别地,我们证明了对于多粒子类薛定谔方程,N粒子波函数在大N处近似等于单粒子波函数的乘积的性质在时间演化下不守恒,虽然已知有限阶的关联函数的相同性质(通过对BBGKY类方程族的分析,证明了这一假设是1956年M.Kac提出的混沌守恒假设的量子类比)。为了找到N粒子波函数的领先渐近性,不仅要利用可由BBGKY方法导出的著名Hartree方程的解,而且要利用本文提出的另一个(Riccati型)方程的解。我们还考虑了另一种有趣的情况,即在所考虑的N粒子系统中再增加一个相互作用势系数为O(1)的粒子,在这种情况下,我们所研究的不是一个类Hartree方程,而是一组类Hartree方程,而且即使对于非线性系统,混沌也不守恒.

英文摘要:

We develop a new method of constructing a large N asymptotic series in powers of $N^{-1/2}$ for the function of N arguments which is a solution to the Cauchy problem for the equation of a special type. Many-particle Wigner, Schrödinger and Liouville equations for a system of a large number of particles are of this type, when the external potential is of order O(1), while the coefficient of the particle interaction potential is 1/N; the potentials can be arbitrary smooth bounded functions. We apply this method to equations for N-particle states corresponding to the N-th tensor power of an abstract Hamiltonian algebra of observables. In particular, we show for the case of multiparticle Schrödinger-like equations that the property of N-particle wave function to be approximately equal at large N to the product of one-particle wave functions does not conserve under time evolution, while the same property for the correlation functions of the finite order is known to conserve(such hypothesis being the quantum analog of the chaos conservation hypothesis put forward by M.Kac in 1956 was proved by the analysis of the BBGKY-like hierarchy of equations). In order to find a leading asymptotics for the N-particle wave function, one should use not only the solution to the well- known Hartree equation being derivable from the BBGKY approach but also the solution to another (Riccati-type) equation presented in this paper. We also consider another interesting case when one adds to the N-particle system under consideration one more particle interacting with the system with the coefficient of the interaction potential of order O(1).It happens that in this case one should investigate not a single Hartree-like equation but a set of such equations, and the chaos will not conserve even for the correlators.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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